CAM plants

I am running very short of information on CAM plants for a report i
have to write
for a class here at my University and I was wondering whether anyone
could direct me to internet sites or books that would better explain the
physiological diferences between them and other plants and the
environmental impact of their existence....
please email me since i am not a habitual reader in this newsgroup...
your help is apprecieated
Aarish
pacha at exis.net